Originally posted by Tzeentch
Tie-Fighters are overall inferior ships that rely on superior numbers to win engagements.
That's not really the case. They rely on superior speed, not swarm tactics, we saw how Poe was impressed by being in one, and they can perform pretty well in equal numbers- they were shooting down X-wings and Y-wings in the first movie, and likely have an edge over the latter.
TIE's vast inferiority largely comes from the video games (and to a lesser extent the X-wing novels, which is about a squadron made of ace pilots).
Now, that said, X-wing having higher toughness (though, I will note, FO TIEs reportedly have shields) and weapons, and an astromech assist, is overall an edge, but it's not a mismatch 1 on 1, it's peer combatants with one having a moderate edge.
And heck, I'd probably bet the First Order Special Forces TIE over an X-wing, due to having a gunner.